Pin-tumbler lock cylinder

ABSTRACT

A lock cylinder is formed having a plurality of projections extending from the periphery of its body in radial directions and having a plurality of pin bores spaced apart by a predetermined distance. The pin bores extend to a keyway in a rotatable barrel housed in the body. Tumbler pins, driver pins and springs are inserted in a desired number of selected pin bores, whereby the lock cylinder is adapted for a vast number of different locking combinations. The rear end of the barrel incorporated in the lock cylinder extends outward from the body of the lock cylinder. Within the keyway, at the extension thereof, there is provided a slidable locking plate which is usually urged by a spring into engagement with a latch portion formed in the body to prevent the rotation of the barrel. The locking plate thus serves as a pickproof means and is freed from locking engagement when a key is inserted into the keyway and acts as an actuating member for the locking mechanism when the barrel is rotated.

United States Patent 91 Sugae [21] Appl. No.: 206,397

[30] Foreign Application Priority Data Dec. 9, 1970 Japan 45/123514 Dec.9, 1970 Japan 45/123515 [52] US. Cl 70/358, 70/380, 70/419 [51] Int. ClE051) 27/06 [58] Field of Search. 70/358, 364 A, 373, 375, 380, 70/401,411, 419, 420, 421, 379 R [56] References Cited UNITED STATES PATENTS2,294,310 8/1942 Larson 70/401 3,348,392 10/1967 Schreiber 70/3583,303,678 2/1967 Bernard 70/375 X 3,123,995 3/1964 Russell 70/379 R3,393,542 7/1968 Crepinsek.... 70/358 977,085 11/1910 Eras 70/4173,413,831 12/196 8 Crepinsek.... 70/358 3,512,382 5/1970 Check 70/358 X3,621,688 ll/l97l Asmar 70/352 Jan. 29, 1974 3/1949 Frizzell.....12/1936 Singer 5 7] ABSTRACT A lock cylinder is formed having aplurality of projections extending from the periphery of its body inradial directions and having a plurality of pin bores spaced apart by apredetermined distance. The pin bores extend to a keyway in a rotatablebarrel housed in the body. Tumbler pins, driver pins and springs areinserted in a desired number of selected pin bores, whereby the lockcylinder is adapted for a vast number of different locking combinations.The rear end of the barrel incorporated in the lock cylinder extendsoutward from the body of the lock cylinder. Within the keyway, at theextension thereof, there is provided a slidable locking plate which isusually urged by a spring into engagement with a latch portion formed inthe body-to prevent the rotation of the barrel. The

locking plate thus serves as a pick-proof means and is freed fromlocking engagement when a key is inserted into the keyway and acts as anactuating member for the locking mechanism when the barrel is rotated.

2 Claims, 9 Drawing Figures "PATENTEDJM 2 1 SHEET 1 BF 2 Fiy. 2

PATENTED M 3,788,110

SHEET 2 BF 2 1 PIN-TUMBLER LOCK CYLINDER BACKGROUND OF THE INVENTIONPick proof locks and locks having different locking combinations areknown from U.S. Pat. Nos. 3,045 ,468 and 3,111,834. However none of theconventional devices have the combined advantages of the device of thepresent invention as described below.

SUMMARY OF THE INVENTION The present invention relates to a pin-tumblerlock cylinder, more particularly to a pin-tumbler lock cylinder adaptedfor different locking combinations by inserting pins and springs inselected pin bores and having at the rear end of its barrel a lockingplate serving as pick-proof means and an actuating member for thelocking mechanism.

An object of this invention is to provide a lock cylinder including abody having on its periphery a plurality of projections each of which isformed with pin bores spaced apart by a uniform distance andcommunicating with a key-way extending through an inner barrel, adesired number of selected pin bores receiving pins therein so as toprovide an increased number of different locking combinations.

Another object of the present invention is to form uniform pin boresspaced apart at a given uniform interval for ease of working, whichbores are formed in a plurality of projections on the periphery of thebody of a lock cylinder and extend from the upper face of theprojections to a key-way through a barrel in the body.

Another object of the present invention is to provide a structurewherein tumbler pins, driver pins and springscan be inserted in placewith ease.

Another object of the present invention is to provide a pick-proof lockwhich can be operated by a key inserted in the keyway.

Another object of this invention is to provide a lock having apick-proof means which serves as an actuator for the locking mechanismwhen the barrel is rotated.

Still another object of this invention is to provide a master keyingsystem by forming a plurality of additional grooves in the key andlongitudinally thereof in conformity with the keyway.

DETAILED DESCRIPTION The body of the lock cylinder of this invention isformed on its circumferential face with radial projections extendingupward and downward or leftward and rightward or upward, leftward, andrightward or upward, downward, leftward and rightward at angles of 180or 90 with respect to each other. With this construction, pin bores areeasier to form in the projections than in the cylindrical body used inconventional structures. The projections thus formed make it convenientto insert pins and the like in the bores and retain the same in place.Moreover, the projections make it easier to fix the cylinder to thelocking mechanism. Thus, two, three, four or more of projections areprovided depending upon the number of different locking combinationsdesired. The projection has a width suitable for forming pin bores andits length is suitably determined in accordance with the number of thedifferent locking combinations. The upper face of the projection isformed with a dovetail groove for receiving a holding plate whichretains the pins and springs within the pin bores.

The opposite ends of the holding plate are bent and secured to theopposite ends of the projection. The pin bores may be formed in eachprojection at an equal interval and with the same diameter. In the casewhere the bores in one projection differ in interval and diameter fromthose in another projection, a greater number of different lockingcombinations will be obtained. Assuming that the total number of boresformed in the respective projections is A and the number of the pinbores receiving therein pins or the like is B, the number of differentlocking combinations will be M= C If A=16 and B=8, for example, thenumber of different locking combinations will be 12,870. It will beapparent that the number of the combinations will be further increasedif the pin bores differ in interval and distance from projection toprojection.

Since the projections are independent of one another, it is easy toinsert the tumbler pins, driver pins and springs into the pin bores.After they are placed in the bores, the holding plate isinsertedprogressively from one end thereof into the dovetail groove tocover the upper end of the projection while depressing the springs oneafter another, whereby they are placed and held in position. In the casewhere the different locking combinations are provided with differinglengths of the bores as heretofore practiced, it has been necessary toblock the upper ends of the bores with filling members one by one.However the present invention does not require such a troublesomeprocedure. With the conventional structure wherein a plurality of rowsof pins are formed in the periphery of the body, it has been necessaryto cover the pins in the pin bores with one cylindrical cover at thesame time, whereas the present invention does not involve such adifficult procedure.

At the rear end of an extension of the barrel, there is provided alocking plate which is slidable within the keyway and which is usuallyurged by a spring into resilient engagement with a latch portion formedin the body to prevent the rotation of the barrel. A pin secured to thebarrel is received in a slot formed in the locking plate, the lockingplate thus being slidably movable within the range of the slot. When akey is inserted into the keyway, the front end of the key pushes thelocking plate against the resilient force of the spring to release thelocking plate from the body, permitting the barrel to rotate.Accordingly, even if a usual picking attempt is made by inserting anarticle other than the key into the keyway to shift the projecting pins,the barrel will be held in place against rotation unless the lockingplate is moved. Thus the present structure includes an effectivepick-proof mechanism. Furthermore, the locking plate which projects in aradial direction at the rear end of the extension of the barrel comesinto engagement, for example, with a retractor or hub included in anunillustrated locking mechanism when the barrel is rotated and drivesthe same to unlatch the locking mechanism. In this way, the lockingplate serves as an actuator for unlocking the locking mechanism. Forthis reason, unlike conventional structure, there is no need to providea separate actuating member at the rear end of the barrel, thus makingit possible to provide a simple mechanism which is serviceable both aspick-proof means and as an actuator.

With reference to drawings illustrating an embodiment, the constructionof the present device will be described in greater detail.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in longitudinalsection showing a lock cylinder including a plurality of rows of pins;

FIG. 2 is a view in section showing the principal part of the lockcylinder, the view illustrating a procedure to insert tumbler pins,driver pins and springs in place and hold the same by a holding platewhich is thereafter caulked;

FIG. 3 is a view in cross section;

FIG. 4 is a view showing the principal part in section as the lockingplate is in engagement with the body of the lock cylinder;

FIG. 5 is a view showing the principal part in section as a key isinserted in the keyway;

FIG. 6 is a perspective view of the lock cylinder with the key insertedtherein;

FIG. 7 is a view in longitudinal section;

FIG. 8 is a plan view showing an example of the key; and

FIG. 9 is a view in cross section showing keys including a master key.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, thereis shown a body 1 including a barrel 2 rotatably housed in the body 1.Pin bores 3 extend through the body 1 and barrel 2 and communicate witha keyway 4. Tumbler pins 5, driver pins 6 and springs 7 are inserted inthe pin bores 3. A holding plate 8 for retaining these pins and springsin position in pressing contact with the springs 7 is secured in place,conveniently by caulking. The body 1 is provided on its periphery with aplurality of projections la, 1b, extending in radial directions. Thepins and springs are accommodated in the projections as described abovein alignment with a key to be inserted in the body. Each of theprojections la, lb, is formed in its upper face with a dovetail groove9. The holding plate 8 is inserted into the groove 9 in sliding contactwith the bottom of the groove and retained therein against upwarddisplacement. The holding plate 8 is bent at its opposite ends andcaulked to the projection. A key 10 has recesses in a correspondingrelation to the pin bores.

To form the bores 3, the barrel 2 is held stationary to the body 1 andbores of the same size are formed in one projection 1a at a giveninterval longitudinally of the body. After this, the same procedure isrepeated on another projection lb. Thus the projections are bored oneafter another separately. A desired number of the pin bores 3individually accommodate tumbler pins 5, driver pins 6 and springs 7,which are retained against jumping out by the holding plate 8 slidablyinserted into the dovetail groove 9 while depressing the upper ends ofthe springs. The holding plate 8 is then bent and caulked to theopposite end of the projection. As a result, the holding plate 8 remainsengaged in the dovetail 9, assuring that the pins and the like areretained in position.

In the keyway 4 at the end of rear extension of the barrel 2, there isprovided a locking plate 11 which is slidably supported in the keyway 4on a pin 13 extending into a slot 12 in the locking plate 11. Thelocking plate projects from the barrel 2 in a radial direction. A spring14 is secured at one end to a cover 15 and is in pressing contact withthe locking plate 11 at the other end. The locking plate 1 l is usuallyurged by the spring 14 into engagement with a latch 16 formed at the endof the body 1. Accordingly, unless the locking plate 11 is pushed out ofengagement by the key 10 inserted into the keyway 4, the barrel 2 isprevented from rotation (see FIG. 4). Thus even when the tumbler pinsare moved by a wire or the like, for instance, in an upward direction topermit the bored portion of the barrel to rotate, the barrel 2 is stillheld against rotation by the locking plate 11 to prevent picking,assuring improved safety.

FIG. 5 shows the state wherein the key 10 is inserted in the keyway 4 tomake the barrel rotatable. More specifically, the locking plate 1 l ispushed by the front end of the key 10 to a retracted position defined bythe slot 12 against the action of the spring 14, rendering the barrel 2rotatable. In this state, the rotation of the barrel 2 causes thelocking plate 11 to rotate. Since the locking plate 1 1 projects outwardin a radial direction, the projected portion will be associated with alocking mechanism such as a boxlike or cylindrical lock, particularlywith a hub thereof. This enables the locking plate 11 to act as anactuating member for unlocking. When the barrel 2 is returned to theoriginal position and the key 10 is pulled out, the locking plate 11 isurged into engagement with the latch portion 16 again under the actionof the spring 14 to bring the lock cylinder to the locking state.

To sum up, the lock cylinder of this invention has a body which servesas a pin cylinder and which is provided with a plurality of projectionsextending in radial directions, with pin bores extending from theprojections through the barrel. Each of the projections accommodates aplurality of tumbler pins, driver pins and springs which are retained inposition by a holding plate. Because of such construction, the presentdevice is easy to manufacture in working and assembleage. In additionthe device is very convenient and useful in that the locking plateassures improved safety and serves as an actuating member for drivingthe hub of a locking mechanism.

As shown in FIG. 8, the key 10 to be used in accordance with thisinvention has recesses 17 corresponding to the pin bores of theprojections and in conformity with the pins accommodated in theprojections. The recesses 17 formed in the key 10 have varying depthsrespectively such that the abutting portions of the tumbler pins anddriver pins of differing lengths can be brought into alignment with theshear line between the body 1 and the barrel 2. The keys 10 shown inFIGS. 8 and 9 are formed with grooves 18 as well as the recesses 17.FIG. 9 shows keys having different sections, A,B, C and D respectivelywith the grooves 18 differing from each other in shape. A master keyingsystem will be obtained with a key having a section E including all ofthese four sections. In accordance with the present invention,therefore, the master keying system provides a number of differentlocking combinations in addition to those obtained by inserting pins ina selected number of the pin bores.

What I claim is:

l. A pin-tumbler lock cylinder including a barrel rotatably disposed ina body of said cylinder, pin bores extending through the body and thebarrel to a keyway and tumbler pins, driver pins and springs inserted insaid pin bores such that different locking combinations are provideddepending upon whether or not said pin 2. The pin-tumbler lock cylinderas set forth in claim 1 wherein when said locking plate is disengageablefrom the latch portion of the body by a key insertable into the keyway,the locking plate is rotated along with the barrel by the rotation ofthe key to come into contact with a locking mechanism and act as anactuating member for an unlocking operation.

1. A pin-tumbler lock cylinder including a barrel rotatably disposed ina body of said cylinder, pin bores extending through the body and thebarrel to a keyway and tumbler pins, driver pins and springs inserted insaid pin bores such that different locking combinations are provideddepending upon whether or not said pin and springs are accommodated in aparticular pin bore, said lock cylinder comprising a locking platedisposed at the end of a rearward extension of the barrel and rotatablysupported in the keyway, said locking plate being slidable within arange defined by a slot formed in said locking plate when a key isinserted in the keyway, said locking plate being mechanically urged intoengagement with a latch portion formed in the body.
 2. The pin-tumblerlock cylinder as set forth in claim 1 wherein when said locking plate isdisengageable from the latch portion of the body by a key insertableinto the keyway, the locking plate is rotated along with thE barrel bythe rotation of the key to come into contact with a locking mechanismand act as an actuating member for an unlocking operation.